#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e6+7;
int f[MAXN];
int vis[MAXN];
bool isOK(int ask, const int& n) {
    memset(f, 0, sizeof(f));
    memset(vis, 0, sizeof(vis));
    int st = 1;
    int t;
    for(int i=0; i<n; ++i) {
        if (f[st]) return false;
        f[st] = ask;
        if (vis[ask]) return false;
        vis[ask] = true;
        t = ask;
        ask = st;
        st = n+1-t;
    }
    return true;
}

int main(int argc, char** argv) {
    int n=0;
    //while (~scanf("%d", &n)) {
    while (n<1000) {
        int res = 0;
        for (int i=2; i<=n; ++i) {
            if (isOK(i, n)) {
                ++res;
            }
        }
        if(res!=0) printf("%d: %d\n", n, res);
        //if (n==1) printf("1\n");
        //else if(n==4) printf("2\n");
        //else printf("0\n");
        ++n;
    }
    return 0;
}
